EDMONTON - Alberta’s forests have received a temporary reprieve in the battle with their most voracious enemy.

Recent ground and aerial surveys show the mountain pine beetle’s progress through the province’s coniferous woodlands has slowed considerably from last year.

The province says extreme cold weather killed off more beetles than usual, while a program of removing infected trees reduced the survivors’ ability to spread to new pines.

“I have to say the work we’ve done, with a little help from Mother Nature, has turned the thing around a bit for this year,” Sustainable Resource Development Minister Mel Knight said.

“But we can’t rest on our laurels. We must continue to be aggressive.”

Knight said there was no indication of a new influx or “inflight” of beetles, such as occurred in 2006 and 2009, when the rice-grain-sized pests were carried into Alberta by high winds from British Columbia.

The province keeps track of infestation levels in part by comparing the number of newly attacked “green” trees with “red” trees that had been infested the year before.

In 2009, Alberta saw a green-red ratio of 40 to 1 and even 170 to 1 in some places.

This year, the average ratio across the province was around 1 to 1.

“We look at how many new beetle-attacked trees we have for each red tree we had last year. And if the ratio is one to one, that tells us the infestation is not growing,” said Duncan MacDonnell, spokesman for Alberta Sustainable Resource Development.

Beetle larvae can usually resist -35 C temperatures for several days but were hit hard this year by extreme fluctuations in the weather, including cold snaps in the spring when the beetles have less natural antifreeze in their bodies. Exceptions were around Grande Prairie and north of Peace River, where beetle populations had better survival rates and consequently attacked more trees.

Knight said he’d like to see more well-timed freezes this year, but the province has also been battling the beetle by cutting down infected trees, along with healthy trees deemed to be the pests’ next targets.

More than $250 million has been spent in Alberta on tree removal and controlled burns, tactics that are likely to continue for the foreseeable future, Knight said.

“I’d love to see eradication but that’s simply not going to happen,” Knight said. “We’re into this thing for the long haul and probably looking at least a decade going forward.”

Allan Carroll, a forest scientist at the University of British Columbia, said the fortunate conditions this year has given Alberta a window of opportunity to put an even bigger dent in beetle numbers.

“It means you don’t relax, but you actually work harder. The fact populations haven’t done as well means that management efforts will have a greater impact,” he said.

“It means that if things turn around next year and it’s suddenly very good for the beetles, the number of new beetles that can be produced is going to be lower because the population will have been reduced.”

Carroll also echoed Knight’s assertion that the province is in for a time-consuming struggle. The long-term trend toward a warming climate is expected to help the beetles.

“They are part of the pine forest now and the forests need to be managed with that in mind in the future,” he said.

The beetle has infected up to three-quarters of British Columbia’s mature lodgepole pines and has attacked an estimated three million trees in Alberta.

Up to six million hectares of forest are threatened, along with the province’s $9-billion forestry industry and its 38,000 jobs.

The beetles kill by tunnelling under the bark and laying eggs, leaving a fungus that interferes with the tree’s vascular system. The larvae then feed on the tree before growing into adults and spreading.

“We’ve seen some positive results but the mountain pine beetle is a pretty dynamic threat,” said Brock Mulligan of the Alberta Forest Products Association. “You can have a bunch of beetles just blow in at any time, so it’s important to stay vigilant.”

Comments

We encourage all readers to share their views on our articles and blog posts. We are committed to maintaining a lively but civil forum for discussion, so we ask you to avoid personal attacks, and please keep your comments relevant and respectful. If you encounter a comment that is abusive, click the "X" in the upper right corner of the comment box to report spam or abuse. We are using Facebook commenting. Visit our FAQ page for more information.

Almost Done!

Postmedia wants to improve your reading experience as well as share the best deals and promotions from our advertisers with you. The information below will be used to optimize the content and make ads across the network more relevant to you. You can always change the information you share with us by editing your profile.

By clicking "Create Account", I hearby grant permission to Postmedia to use my account information to create my account.

I also accept and agree to be bound by Postmedia's Terms and Conditions with respect to my use of the Site and I have read and understand Postmedia's Privacy Statement. I consent to the collection, use, maintenance, and disclosure of my information in accordance with the Postmedia's Privacy Policy.

Postmedia wants to improve your reading experience as well as share the best deals and promotions from our advertisers with you. The information below will be used to optimize the content and make ads across the network more relevant to you. You can always change the information you share with us by editing your profile.

By clicking "Create Account", I hearby grant permission to Postmedia to use my account information to create my account.

I also accept and agree to be bound by Postmedia's Terms and Conditions with respect to my use of the Site and I have read and understand Postmedia's Privacy Statement. I consent to the collection, use, maintenance, and disclosure of my information in accordance with the Postmedia's Privacy Policy.